were investigating after their officers shot and killed a man accused of stabbing his own brother-in-law. it happened in the portrero hills neighborhood. the suspect called 9-1-1 to report the stabbing around 9:45 and police got there in minutes of the call and they say the suspect came after them with a hammer. the police chief explains what happened next. >> the officers ordered the person to step his advance and he continues the advance. an officer fired upon the suspects, and 9 suspect went to the ground and this is corroborated by independent witness testimony. >> the victim suffered serious injuries do his head, arms and chest but he is expected to survive. >> this morning, you can feel it is chilly. >> that is because of the lack of wind. mike? >> we have been talking about no wind, nothing to keep the manufacture stirred so that is why the cold heavy earth sinks and the warm air prices and why we have cooler conditions this morning. we have dry air out there and you can see on live doppler 7 hd no radar runs. the air mass as far as pollen is concerned has been rough all week. fro